A method is disclosed for making on a transparent receiver material a continuous tone image, e.g. for medical diagnostic purposes, with an obtainable maximal transmission density in the visual region greater than 3.0, by means of ink jet. The method comprises ink-jetting combinations of at least one liquid black pigmented ink and at least one liquid grey ink to a transparent receiver comprising an ink receiving layer, a transparent support and a backing layer, said ink receiving layer comprising a N-containing polymer, preferably gelatin, as binder, and being substantially free of particles having an average size larger than 1 xcexcm. Preferably the transparent receiver exhibits a haze value between 10 and 20%, determined according to standard test ASTM D 1003, due to the presence of a spacing agent in the backing layer.

The present invention relates to an ink jet method with improved tonal range and high obtainable maximal density. The method is useful for the rendering of medical diagnostic information.
In the majority of applications printing proceeds by pressure contact of an ink-loaden printing form with an ink-receiving material which is usually plain paper. The most frequently used impact printing technique is known as lithographic printing based on the selective acceptance of oleophilic ink on a suitable receptor.
In recent times however so-called non-impact printing systems have replaced classical pressure-contact printing to some extent for specific applications. A survey is given e.g. in the book xe2x80x9cPrinciples of Non Impact Printingxe2x80x9d by Jerome L. Johnson (1986), Palatino Press, Irvine, Calif. 92715, USA.
Among non-impact printing techniques ink jet printing has become a popular technique because of its simplicity, convenience and low cost. Especially in those instances where a limited edition of the printed matter is needed ink jet printing has become a technology of choice. A recent survey on progress and trends in ink jet printing technology is given by Hue P. Le in Journal of Imaging Science and Technology Vol. 42 (1), January/February 1998.
In ink jet printing tiny drops of ink fluid are projected directly onto an ink receptor surface without physical contact between the printing device and the receptor. The printing device stores the printing data electronically and controls a mechanism for ejecting the drops image-wise. Early patents on ink jet printers include U.S. Pat. No. 3,739,393, U.S. Pat. No. 3,805,273 and U.S. Pat. No. 3,891,121.
The jetting of the ink droplets can be performed in several different ways. In the early 1960s, Dr. Sweet of Stanford University demonstrated that by applying a pressure wave pattern to an ink stream which is jetted continuously through a small nozzle. This ink stream could be broken in droplets which are uniform in size and spacing. The droplet stream is image-wise divided into droplets that are electrostatically charged and deflected, and into droplets that remain uncharged and continue their way undeflected. This process is known as continuous ink jet printing. In one embodiment the uncharged undeflected droplet stream forms the image while the charged deflected stream is recollected. Alternatively, the charged deflected stream forms the image and the uncharged undeflected jet is recollected. In still a further variant of the latter system several jets are deflected to a different degree and thus record the image (multideflection system). Sweet""s invention led to the introductions of A.B. Dick VideoJet and the Mead DIJIT products. In the 1970s IBM licensed the technology and adapted it for their computer printers. At approximately the same time, Prof. Hertz of the Lund Institute of Technology in Sweden and his associates independently developed several continuous ink jet techniques that had the ability to modulate the ink flow characteristics for gray-scale printing by controlling the number of drops deposited in each pixel. This method was licensed to companies such as Iris Graphics/Scitex and Stork to produce high-quality colour images.
As an alternative for continuous ink jet the ink droplets can be created xe2x80x9con demandxe2x80x9d (xe2x80x9cDODxe2x80x9d or xe2x80x9cdrop on demandxe2x80x9d method) whereby the printing device ejects the droplets only when they are used in imaging on a receiver thereby avoiding the complexity of drop charging and deflection hardware. In drop-on-demand the ink droplet can be formed by means of a piezoelectric transducer (so-called xe2x80x9cpiezo methodxe2x80x9d), or by means of discrete thermal pushes (so-called xe2x80x9cbubble jetxe2x80x9d method, or xe2x80x9cthermal jetxe2x80x9d method). Zoltan, Kyser and Sears are the pioneers of the first method. In these printers, on the application of voltage pulses, ink drops are ejected by a pressure wave created by the mechanical motion of a piezoelectric ceramic. In 1979, Endo and Hara of Canon Co. invented a drop-on-demand ink jet method wherein ink drops were ejected from a nozzle by the growth and collapse of a water vapor bubble on the top surface of a small heater located near the nozzle. Canon called the technology the bubble jet. During the same time period or shortly thereafter Hewlett-Packard developed a similar ink jet technology, commercialized in 1984 in the Thinkjet printer. They named the technology thermal ink jet.
Ink jet printing technologies are used in a wide range of applications such as desktop publishing at home or at office, industrial printing of packings, e.g. with barcodes, printing of cables, prints from photographs generated from an electronic camera, outdoor advertisement, textile printing; three-dimensional printing, etc. An emerging market is surely ink jet printing of electronically stored medical information. Key players are the companies Scitex/Iris and Sterling Diagnostics. Also Misubishi Plastics recently announced the development of a film that can be imaged with ink jet to print medical images (Japan Chemical Week, (Apr. 9, 1998, p. 1). Hitherto images comprising medical information were conventionally produced by classical photographic techniques. The most commonly used is silver halide technology. After image-wise exposure by X-rays, converted to actinic radiation by means of a phosphor screen, or by a laser beam the film must be processed in baths containing dissolved chemicals. This however is a cumbersome and ecologically undesired procedure. Therefore environmently friendlier materials were recently introduced based on thermographic or photothermographic technologies such as Imation Dryview films and Agfa Drystar. These technologies however need expensive apparatuses based on laser or thermal head imaging. Ink jet could be an inexpensive and ecologically acceptable alternative to the systems mentioned above provided it would be capable of producing continuous tone images with a sufficient number, preferably at least 100, of grey levels, high maximal transmission density, low noise level, and neutral grey tone.
As already mentioned above grey-scale printing can be performed by the Hertz method by controlling the number of droplets deposited in each pixel. A sufficient number of grey levels can also be obtained by combining droplets of different inks having the same colorant but in different concentrations. The principle was already disclosed in U.S. Pat. No. 3,404,221, priority U.S. Pat. No. 22.10.1965. Specific embodiments of the method of combinations of several inks of different densities are disclosed e.g. in DE 3415778, DE 3415775, U.S. Pat. No. 4,533,923, U.S. Pat. No. 4,695,846, U.S. Pat. No. 4,714,964, U.S. Pat. No. 4,686,538, U.S. Pat. No. 4,952,942, U.S. Pat. No. 4,860,026, EP 388978, EP 606022, U.S. Pat. No. 5,606,351, U.S. Pat. No. 5,625,397, and EP 750995. Furtheron grey scale images can be produced by modulation of the ink droplet size as explained in the article xe2x80x9cPhoto-realistic ink jet printing through dynamic spot size controlxe2x80x9d, by D. Wallace et al., presented at IS and T""s Eleventh International Congress on Advances in Non-Impact Printing, Oct. 29-Nov. 3, 1995, Hilton Head, South Carolina. Furtheron combinations of these different methods can be used.
According to the article xe2x80x9cContinuous Ink Jet Printing of Medical imagesxe2x80x9d presented at the RSNA congress, November 1993, in Chicago Dr. Philp Drew of Scitex Co. demonstrated the production of multi-grey images by the UniTone ink jet printer based on the combinations of black and grey inks, meaning neutral inks with different colorant concentrations, in combinations with variable dot sizes. These images however were printed on reflective receivers. In this case the reflection density does not increase indefinitly in a linear way as a function of the number of dots per pixel, but becomes almost constant at a density of about 1.6, as explained in the article xe2x80x9cEnhanced Density Resolution with Continuous Ink Jet Printing Using Dual Ink Densitiesxe2x80x9d by T. Kirkhorn et al., J. Imag. Sci. Tech., Vol. 36 (1), January/February. 1994, p. 74-80. Therefore the Unitone images cannot be regarded as having the real image quality as required for medical diagnostic imaging.
So far transmission densities higher than 3.0 could only be reached by ink jet printers using so-called hot melt or phase change inks which are solid at ambient temperature. Sterling in cooperation with Tektronix presented the first ink jet system for the production of true medical diagnostic images on transparent receivers at the RSNA congress, November 1996. Hot melt inks however have several disadvantages over the liquid inks. Before printing the inks must be brought in a molten state which takes start-up time and requires a more complex and expensive printer. The produced images look and feel greasy and have a low scratch resistance so that the image can be damaged when handled uncarefully.
In an alternative attempt to reach high densities so-called reactive systems were developed wherein the ink image was enhanced by a silver image obtained by reduction of an organic silver salt, preferably silver behenate, incorporated in the ink composition or in the receiving layer as disclosed in EP 691211 and EP 641670. However these systems are complicated, require a heat treatment and are therefore commercially unattractive.
It is an object of the present invention to provide an ink jet printing method, particularly suited for reproduction of medical diagnostic information, which is capable to produce maximal densities higher than 3.0.
It is a further object of the present invention to provide an ink jet printing method that reaches the goal mentioned above by using conventional liquid inks.
The objects of the present invention are realized by providing a method comprising ink-jetting combinations of at least one liquid black pigmented ink and at least one liquid grey ink to a receiver material comprising an ink receiving layer, a transparent support and a backing layer, said ink receiving layer comprising at least one N-containing polymer, and being substantially free of particles having an average size larger than 1 xcexcm
The N-containing polymer present as binder in the ink receiving layer is preferably gelatin.
In a preferred embodiment the receiver material exhibits a haze value between 10 and 20%, determined according to standard test ASTM D 1003, due to the presence of a spacing agent in the backing layer.
The receiving layer of the receiver material of the present invention may consist of just one single layer or can be coated as a multiple layer pack, e.g. a double layer. The receiving layer or layer pack comprises as main ingredients a binder which is a N-containing polymer. Farout the most preferred binder is gelatin. The advantages of gelatin are the facts that it forms a clear coating, is readily cross-linked in an easily controllable manner, and is highly absorptive of water-based liquid inks thereby providing rapid drying characteristics. Other N-containing binders can be chosen from a large variety of chemical compounds including e.g. polyvinyl pyrrolidone (PVP), polyacrylamide, acrylamide/ acrylic acid, poly(2-acrylamido-2-methyl propane sulphonic acid), poly(diethylene triamine-co-adipic acid), polyvinyl pyridine, polyvinyl imidazole, quaternized polyimidazoline, polyethylene imine epichlorohydrine modified, ethoxylated polyethylene imine, poly(N,N,-dimethyl-3,5-dimethylene piperidinium chloride, polyurethene, melamin resins, urea resins, nitrile rubbers, albumin.
More than one N-containing polymer can be present in the receiving layer. In a preferred embodiment gelatin is mixed with polyvinyl pyrrolidone (PVP).
In principle, although not being a preferred embodiment, a non-N-containing binder may also be present in the receiving layer, e.g. cellulose derivatives such as hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose; starch, dextran; polyvinyl alcohol, polyvinyl acetate, polyvinyl acetal, polyalkyleneoxides, film-forming latices such as copoly(styrene-butadiene), carboxylated polymers, polyacrylates, etc.
The receiving layer can further contain fillers, pigments, whitening agents and porous particulate material for as far as these compounds have an average particle size smaller the 1 xcexcm. By setting this upper limit to the average particle size it is made sure that these compounds cannot be regarded as matting or spacing agents and that they do not decrease the transmission density of the ink applied. Inorganic materials include e.g. synthetic silica, talc, clay, koalin, diatomaceous earth, calcium carbonate, magnesium carbonate, aluminium hydroxide, aluminium oxide, boehmite and pseudo-boehmite, titanium oxide, zinc oxide, barium sulfate, calcium sulfate, zinc sulfide, satin white, aluminium silicate, calcium silicate, lithopone, etc. Organic materials (with the same particle size limitation) include e.g. polystyrene, polymethacrylate, polymethylmethacrylate, elastomers, ethylene-vinylacetate copolymers, polyesters, polyester-copolymers, polyacrylates polyvinylethers, polyamides, polyolefines, polysilicones, guanamine resins, polytetrafluoroethylenes, elastomeric styrene-butadiene rubber (SBR), elastomeric butadiene-acrylonitrile rubber, urea resins, urea-formalin resins, etc. Pigments and particles have also been described in patent applications DE 2,925,769, GB 2,050,866, U.S. Pat. No. 4,474,850, U.S. Pat. No. 4,547,405, U.S. Pat. No. 4,578,285, WO 88 06532, U.S. Pat. No. 4,849,286, EP 339 604, EP 400 681, EP 407 881, EP 411 638 and U.S. Pat. No. 5,045,864.
Again, the presence of modifications of these compounds with an average particle size higher than 1 xcexcm is excluded from the scope of the invention.
Further typical and useful ingredients of ink jet receiver layers are so-called mordanting agents which by fixing the colorant of the jetted ink composition strongly improve the waterfastness of the finished image. Such mordant are usually (co)polymers containing cationic functions such as quaternary ammonium groups, fosfonium, sulfonium, and guadinium groups. Examples of such disclosures include U.S. Pat. No. 4,371,582, U.S. Pat. No. 4,575,465, U.S. Pat. No. 4,649,064, GB 2210071, EP 423829, DE 3109931, U.S. Pat. No. 4,585,724, EP 295338, EP 306564, U.S. Pat. No. 5,314,747, EP 609930, WO 94/20304, WO 94/20305, WO 94/20306, EP 615853, EP 615884, EP 618214, Also inorganic mordants have been described e.g. in U.S. Pat. No. 5,560,996, EP 704316, EP 754560.
The ink receiving layer according to this invention may be cross-linked to provide such desired features as water-fastness and non-blocking characteristics. The cross-linking is also useful in providing abrasion resistance and resistance to the formation of fingerprints on the element as a result of handling. There are a vast number of known cross-linking agents, also known as hardening agents that can be used individually or in combination and in free or in blocked form. Useful hardeners include formaldehyde and free dialdehydes, such as succinaldehyde and glutaraldehyde, blocked dialdehydes, active esters, sulfonate esters, active halogen compounds, s-triazines and diazines, epoxides, active olefins having two or more active bonds, active olefins, carbodiimides, isoxazolium salts unsubsituted in the 3-position, esters of 2-alkoxy-N-carboxy-dihydro-quinoline, N-carbamoyl and N-carbamoylpyridinium salts, hardeners of mixed function, such as halogen-substituted aldehyde acids (e.g. mucochloric and mucobromic acids), onium substituted acroleins and vinyl sulfones and polymeric hardeners, such as dialdehyde starches and copoly(acroleinmethacrylic acid).
The ink-receiving layer of the present invention can also comprise a plasticizer such as ethylene glycol, dietylene glycol, propylene glycol, polyethylene glycol, glycerol monomethylether, glycerol monochlorohydrin, ethylene carbonate, propylene carbonate, tetrachlorophthalic anhydride, tetrabromophthalicanhydride, urea phosphate, triphenylphosphate, glycerolmonostearate, propylene glycol monostearate, tetramethylene sulfone, N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, and polymer latices with low Tg value such as polyethylacrylate, polymethylacrylate, etc.
Surfactants may be incorporated in the ink-receptive layer of the present invention. They can be any of the cationic, anionic, amphoteric, and nonionic ones as described in JP-A 62-280068 (1987). Examples of the surfactants are N-alkylamino acid salts, alkylether carboxylic acid salts, acylated peptides, alkylsulfonic acid salts, alkylbenzene and alkylnaphthalene sulfonic acid salts, sulfosuccinic acid salts, olefin sulfonic acid salts, N-acylsulfonic acid salts, sulfonated oils, alkylsulfonic acid salts, alkylether sulfonic acid salts, alkylallylethersulfonic acid salts, alkylamidesulfonic acid salts, alkylphosphoric acid salts, alkyletherphosphoric acid salts, alkylallyletherphosphoric acid salts, alkyl and alkylallylpolyoxyethylene ethers, alkylallylformaldehyde condensed acid salts, alkylallylformaldehyde condensed polyoxyethylene ethers, blocked polymers having polyoxypropylene, polyoxyethylene polyoxypropylalkylethers, polyoxyethyleneether of glycolesters, polyoxyethyleneether of sorbitanesters, polyoxyethyleneether of sorbitolesters, polyethyleneglycol aliphatic acid esters, glycerol esters, sorbitane esters, propyleneglycol esters, sugaresters, fluoro C2-C10 alkylcarboxylic acids, disodium N-perfluorooctanesulfonyl glutamate, sodium 3-(fluoro-C6-C11-alkyloxy)-1-C3-C4 alkyl sulfonates, N-[3-(perfluorooctanesulfonamide)-propyl]-N,N-dimethyl-N-carboxymethylene ammonium betaine, fluoro-C11-C20 alkylcarboxylic acids, perfluoro C7-C13 alkyl carboxylic acids, perfluorooctane sulfonic acid diethanolamide, Li, K and Na perfluoro C4-C12 alkyl sulfonates, N-propyl-N-(2-hydroxyethyl)perfluorooctane sulfonamide, perfluoro C6-C10 alkylsulfonamide propyl sulfonyl glycinates, bis-(N-perfluorooctylsulfonyl-N-ethanolaminoethyl)phosphonate, mono-perfluoro C6-C16 alkyl-ethyl phosphonates, and perfluoroalkylbetaine.
The image-receiving layers of the present invention may additionally comprise additives which are well known in the art, such as UV-absorbers, e.g. as disclosed in e.g. U.S. Pat. No. 4,926,190, antistatic agents, and others.
Useful transparent organic resin supports include e.g. cellulose nitrate film, cellulose acetate film, polyvinylacetal film, polystyrene film, polyethylene terephthalate film, polycarbonate film, polyvinylchloride film or poly-xcex1-olefin films such as polyethylene or polypropylene film. The thickness of such organic resin film is preferably comprised between 0.05 and 0.35 mm. In a most preferred embodiment of the present invention the support is a polyethylene terephthalate film provided with at least one subbing layer. This subbing layer can be applied before or after stretching of the polyester film support. The polyester film support is preferably biaxially stretched at an elevated temperature of e.g. 70-120xc2x0 C., reducing its thickness by about xc2xd to {fraction (1/9)} or more and increasing its area 2 to 9 times. The stretching may be accomplished in two stages, transversal and longitudinal in either order or simultaneously. The subbing layer, when present, is preferably applied by aqueous coating between the longitudinal and transversal stretch, in a thickness of 0.1 to 5 mm. This subbing layer preferably contains a homopolymer or copolymer of a monomer comprising covalently bound chlorine. Examples of said homopolymers or copolymers suitable for use in the subbing layer are e.g. polyvinyl chloride, polyvinylidene chloride, a copolymer of vinylidene chloride, an acrylic ester and itaconic acid, a copolymer of vinyl chloride and vinylidene chloride, a copolymer of vinyl chloride and vinyl acetate, a copolymer of butylacrylate, vinyl acetate and vinyl chloride or vinylidene chloride, a copolymer of vinyl chloride, vinylidene chloride and itaconic acid, a copolymer of vinyl chloride, vinyl acetate and vinyl alcohol etc. Polymers that are water dispersable are preferred since they allow aqueous coating of the subbing layer which is ecologically advantageous.
A second subbing layer may be present which is usually more hydrophilic and contains e.g. gelatin and an adhesion promoting polymer.
The polyester support can be blue coloured as it is also often the case with silver halide medical imaging films.
The support may be a mono-component layer or can consist of blend, or of a laminate of different materials manufactured by means of coextrusion.
In a most preferred embodiment of the present invention the receiving element exhibits a haze value between 10 and 20% which is desirable for the visual interpretation of the final continuous tone image, particlarly when this image is the reproduction of medical diagnostic information. The haze value is determined according to standard test ASTM D 1003. This is preferably realized by the incorporation of a spacing agent in the backing layer. The term xe2x80x9cspacing agentxe2x80x9d should be interpreted in its broad sense and as being equivalent to xe2x80x9cmatting agentxe2x80x9d and xe2x80x9croughening agentxe2x80x9d. The presence of the spacing agent improves the transport in the printer, avoides the sticking of sheets to each other, and prevents the rubbing-off of the ink jet image or the transfer of a previously printed image.
The nature of the matting particles present in the backing layer is not limited to a specific chemical type but can be chosen from a wide variety of chemical classes and commercial products as revealed in scientific and patent literature from the ink jet field itself or from other imaging technologies such as silver halide photography. Useful roughening agents include following:
different types of silica such as disclosed e.g. in U.S. Pat. No. 3,084,131, U.S. Pat. No. 4,892,591, U.S. Pat. No. 4,902,568, EP 379964, EP 423829, U.S. Pat. No. 5,165,973, EP 739747, EP 781666, EP 803374, EP 862510, Wo 97/20691
starch or modified starch particles such as disclosed in EP 445327, EP 480362, EP 524635;
the spherical polymeric beads disclosed in U.S. Pat. No. 4,861,818
the alkali-soluble beads of U.S. Pat. No. 4,906,560 and EP 0 584 407
the insoluble polymeric beads disclosed in EP 0 466 982
polymethylmethacrylate beads;
copolymers of methacrylic acid with methyl- or ethylmethacrylate;
TOSPEARL siloxane particles (e.g. types T105, T108, T103, T120), marketed by Toshiba Co;
SEAHOSTAR polysiloxanexe2x80x94silica particles (e.g. type KE-P50), marketed by Nippon Shokubai Co;
EPOSOAR MA particles;,these are polymethylmethacrylate (PMMMA) X-linked (e.g. MA 1002, MA 1004);
SOKEN PEARL: spherical PMMMA micro powders (AS series :e.g. AS 15, 22, 30, 50, 65);
ROPAQUE particles, being polymeric hollow spherical core/sheat beads, marketed by Rohm and Haas Co, and described e.g. is US-P""s 4,427,836, 4,468,498 and 4,469,825;
ABD PULVER, marketed by BASF AG
CHEMIPEARL, spherical poymeric particles, marketed by Misui Petrochemical Industries, Ltd.;
particles coated with a water-repellent material such as disclosed in U.S. Pat. No. 5,204,233;
polymer particles having a reactive functional group capable of forming a covalent bond with a hardener or a binder, as disclosed in U.S. Pat. No. 5,057,407;
fluorine containing polymer pearls as described in EP 281928;
polymer particles prepared by suspension polymerisation as described e.g. in U.S. Pat. No. 5,342,733;
particles containing two polymers prepared as described by the method of EP 399729;
polystyrene beads prepared as disclosed in EP 341200;
gelatin-grafted polymer matting agents according to EP 307855.
The presence of a matting agent in the backing layer itself of an ink jet receiving material is disclosed in e.g.:
JP-A 7-179025: backing layer contains spherical particles having an average size of 5-15 xcexcm, e.g. spherical polystyrene particles of 5 xcexcm;
U.S. Pat. No. 5,190,805 and corresponding EP 533293, and U.S. Pat. No. 5,206,071 and corresponding EP 545470 disclose specific receiver materials with a coarse matting agent in the backing layer.
A preferred type of matting agent is a hydrophobic modified starch. An example of such a modified starch is commercialized under the trade name xe2x80x9cDRY FLOxe2x80x9d by Roquette National Chimie. It is a starch ester containing hydrophobic groups. Its average particle diameter (median) according to volume is comprised between 13 and 20 xcexcm.
The backing layer may further contain essentially the same ingredients as the receiving layer.
Ink compositions for ink jet typically include following ingredients: dyes or pigments, water and/or organic solvents, humectants such as glycols, detergents, thickeners. polymeric binders, preservatives, etc. It will be readily understood that the optimal composition of such an ink is dependent on the ink jetting method used and on the nature of the substrate to be printed. The ink compositions can be roughly divided in:
water based; the drying mechanism involves absorption, penetration and evaporation;
oil based; the drying involves absorption and penetration;
solvent based; the drying mechanism involves evaporation;
hot melt or phase change: the ink vehicle is liquid at the ejection temperature but solid at room temperature; drying is replaced by solidification;
radiation curable, e.g. UV-curable; drying is replaced by polymerization.
It will be readily understood that the first three types of ink compositions require a receiving medium that is more or less absorptive. On the contrary, for non-absorbent substrates hot melt inks or radiation-curable inks will be better suited.
According to the present invention combinations of liquid inks, preferably water-based inks are used. Hot melt inks are explicitly excluded.
Early patents on water-based inks include U.S. Pat. No. 3,903,034, U.S. Pat. No. 3,889,269, U.S. Pat. No. 3,870,528, U.S. Pat. No. 3,846,141, U.S. Pat. No. 3,776,742 and U.S. Pat. No. 3,705,043.
Typically water-based inks contain about 75-90 weight % of water. In order to avoid dry tipping on the orifice they contain a so-called humectant or mixtures of humectants which usually are (poly)alcohols. Suitable humectants include glycols such as diethyleneglycol, glycerine and polyethyleneglycol, N-methyl-pyrrolidone, 2-pyrrolidone, N-methyl-2-pyrrolidone, isopropanol, and 1,2-dimethyl-2-imidazolidone. Certain humectants such as N-methyl-pyrrolidone and 2-pyrrolidone have been found to improve the solubility of the colorant in the ink and thus serve the dual role as humectant and as cosolvent. Typically these humectants are present in a concentration ranging from 5 to 15%.
Apart from the colorant, water and humectant water-based ink compositions may contain in minor amounts further ingredients such as surfactants, biocides, buffering agents, chelating agents and defoaming agents.
It is essential that one of the ink compositions used in the process of the present invention is a concentrated black pigmented ink. Preferably the black pigment is carbon black in a concentration of at least 2%, preferably about 5%. Multiple types of inks containing carbon black are commercially available. Examples of useful carbon blacks include Regal 400R, Mogul L, Elftex 320 from Cabot Co., or Cardon Black IW18, Special Black 250, Special Black 350, Special Black 550, Printex 25, Printex 35, Printex 55, Printex 150T from Degussa Co., and Pigment Black 7.
According to the present invention combinations are jetted to the receiver of this concentrated black ink and at least one other grey ink. A grey ink is defined as an ink capable of producing a lower density than the black ink under identical printing conditions. The grey ink(s) can be simply (a) dilution(s) of the concentrated black ink. The ratios of the concentrations of the different inks must be chosen so that in combination with the print method used a linear tone rendering can be obtained over the whole printable density range. The linearisation of the visual perception curve must be taken into account. The ratios chosen are also function of the maximal number of overlapping droplets per dot. Furtheron, the screening algorithm may play a role in the choice of the optimal ratios.
Alternatively, the diluted grey inks can be compositions containing a mixture of a cyan colorant, a magenta colorant and a yellow colorant in such a ratio that again a grey ink is obtained. However, this is not the preferred option since it is difficult with a mixture of colorants to obtain a neutral hue over the whole tonal range due to their spectral side absorptions.
The colorants can be pigments or dyes.
Suitable pigments include, for instance, C. I. Pigment Yellow 17, C. I. Pigment Blue 27, C. I. Pigment Red 49:2, C. I. Pigment Red 81:1, C. I. Pigment Red 81:3, C. I. Pigment Red 81:x, C. I. Pigment Yellow 83, C. I. Pigment Red 57:1, C. I. Pigment Red 49:1, C. I. Pigment Violet 23, C. I. Pigment Green 7, C. I. Pigment Blue 61, C. I. Pigment Red 48:1, C. I. Pigment Red 52:1, C. I. Pigment Violet 1, C. I. Pigment White 6, C. I. Pigment Blue 15, C. I. Pigment Yellow 12, C. I. Pigment Blue 56, C. I. Pigment Orange 5, C. I. Pigment Black 7, C. I. Pigment Yellow 14, C. I. Pigment Red 48:2, C. I. Pigment Blue 15:3, C. I. Pigment Yellow 1, C. I. Pigment Yellow 3, C. I. Pigment Yellow 13, C. I. Pigment Orange 16, C. I. Pigment Yellow 55, C. I. Pigment Red 41, C. I. Pigment Orange 34, C. I. Pigment Blue 62, C. I. Pigment Red 22, C. I. Pigment Red 170, C. I. Pigment Red 88, C. I. Pigment Yellow 151, C. I. Pigment Red 184, C. I. Pigment Blue 1:2, C. I. Pigment Red 3, C. I. Pigment Blue 15:1, C. I. Pigment Red 23, C. I. Pigment Red 112, C. I. Pigment Yellow 126, C. I. Pigment Red 169, C. I. Pigment Orange 13, C. I. Pigment Red 1-10, 12, C.I. Pigment Blue 1:X, C.I. Pigment Yellow 42, C.I. Pigment Red 101, C.I. Pigment Brown 6, C.I. Pigment Brown 7, C. I. Pigment Brown 7:X, C.I. Pigment Black 11, C.I. Pigment Metal 1, or C.I. Pigment Metal 2.
Furtheron the pigment may be chosen from those disclosed in Industrial Organic Pigments, Production, Properties, Applications, second edition, W. Herbst, K. Hunger; VCH, 1997. Additional examples of suitable pigments are disclosed in, for example, U.S. Pat. No. 5,389,133 and U.S. Pat. No. 5,713,988.
The pigment particles should be sufficiently small to permit free flow of the ink through the ink jet printing device, especially at the ejecting nozzles that usually have a diameter ranging from less than 10 microns to 50 microns. The pigment particle size also has an influence on the pigment dispersion stability, which is critical throughout the life of the ink. It is also desirable to use small particles for maximum color strength.
Accordingly, the average particle diameter may be from about 0.005 xcexcm to about 15 xcexcm. Preferably, the pigment particle size may range from about 0.005 to about 5 xcexcm, more preferably from about 0.005 to about 1 xcexcm, and most preferably from about 0.005 to about 0.3 xcexcm. Pigment particle sizes outside these ranges may, of course, be used as long as the objectives of the present invention are achieved.
Very fine dispersions of pigments and methods for their preparation are disclosed in e.g. EP 0 776 952, U.S. Pat. No. 5,538,548, U.S. Pat. No. 5,443,628, EP 0 259 130, U.S. Pat. No. 5,285,064, EP 0 429 828, and EP 0 526 198.
Suitable dyes include e.g. Orasol Pink 5BLG, Blue 2GLN, Red G, Yellow 2GLN, Blue GN, Blue BLN, Brown CR, Neolan Blue, all available from Ciba-Geigy Co.; Morfast Blue 100, Red 101, Red 104, Yellow 102, all available from Morton Chemical Co, Ajax, Ontario; Bismark Brown R, available from Aldrich; Savinyl Yellow RLS, Red 3 GLS, Pink GBLS, all available from Sandoz Co.
Apart from the use of combinations of differently concentrated inks the grey scale reproduction method according to the present invention can make use of multiple dot printing onto one pixel, and/or of dot size modulation, as mentioned in the Background section. Also combinations of the foregoing methods can be used.
It will be clear that the essential medical information is recorded in neutral grey, but, in principle, so-called spot colours can be added to the image at particular parts.

Ink jet method with improved tonal range


A log catcher for catching and holding logs which fall from a log splitter which is supported upon an I-beam. The log catcher comprises five parallel cylindrical rods each having two ends, a horizontal first cross-beam attached to the rods at one end, and a horizontal second cross-beam attached to the rods at the other end. The log catcher further comprises an angular cross-beam having evenly spaced holes through which the rods extend at a point which is substantially closer to the second cross-beam than to the first cross-beam. All five rods are evenly spaced throughout. Each rod has a right angle bend, thereby forming a curved portion, wherein the falling logs may be effectively contained. In use, the log catcher is positioned below the I-beam, and the second cross-beam and the angular cross-beam effectively bracket the lower surface of the I-beam, thereby imparting additional stability to the log catcher.

1. Field of the Invention
The invention relates to a log catcher for use in receiving and holding logs which have been cut by a log splitter.
2. Description of the Related Art
A variety of devices are available for splitting logs. U.S. Pat. No. 4,487,239 to Anderson appears to show a log splitter with an automatic hoist for lifting logs onto the platform of the splitter. U.S. Pat. No. 4,239,070 to Burns appears to show a log splitter in which two splitting edges are employed. However, noticeably absent from these devices is a log catcher for receiving and holding the split logs when they have fallen from the log splitter. Accordingly, there is a need for a device which may be appended to an existing log splitter for catching the split logs as they fall from the log splitter.
U.S. Pat. No. 4,461,331 to Mertz appears to show a log splitter with a log catcher incorporated to receive the split logs. However, the log catcher in Mertz is an integral part of the log splitting device. Accordingly, Mertz fails to provide a log catcher which may be used with an existing log splitter.
While these units may be suitable for the particular purpose employed, or for general use, they would not be as suitable for the purposes of the present invention as disclosed hereafter.
It is an object of the invention to produce a log catcher which may be readily used with existing log splitters supported upon I-beams. Accordingly, the log catcher is ready for use after a portion of the log catcher is placed underneath and brackets the I-beam.
It is another object of the invention to produce a log catcher which is rugged enough to withstand repeated impacts from falling logs. Accordingly, the log catcher is constructed of metal and will not be damaged by logs as they fall onto the log catcher.
It is yet another object of the invention to produce a log catcher which is not overly complicated. Accordingly, the log catcher is simply constructed from five rods which are joined at various positions along their length by three horizontal beams.
It is still yet another object of the invention to produce a log catcher which is not unduly expensive. Accordingly, the log catcher is constructed from inexpensive materials, so that its cost is not prohibitive.
It is still another object of the invention to produce a log catcher which remains immobile, even when impacted by falling logs. Accordingly, the log catcher is stabilized by the weight of the I-beam and the log splitter, and it will not move when it is impacted by falling logs.
It is an additional object of the invention to produce a log catcher which is easy to use. Accordingly, the log catcher requires no maintenance, and a user simply removes the fallen logs from the log catcher when they have accumulated.
The invention is a log catcher for catching and holding logs which fall from a log splitter which is supported upon an I-beam. The log catcher comprises five parallel cylindrical rods each having two ends, a horizontal first cross-beam attached to the rods at one end, and a horizontal second cross-beam attached to the rods at the other end. The log catcher further comprises an angular cross-beam having evenly spaced holes through which the rods extend at a point which is substantially closer to the second cross-beam than to the first cross-beam. All five rods are evenly spaced throughout. Each rod has a right angle bend, thereby forming a curved portion, wherein the falling logs may be effectively contained. In use, the log catcher is positioned below the I-beam, and the second cross-beam and the angular cross-beam effectively bracket the lower surface of the I-beam, thereby imparting additional stability to the log catcher.
To the accomplishment of the above and related objects the invention may be embodied in the form illustrated in the accompanying drawings. Attention is called to the fact, however, that the drawings are illustrative only. Variations are contemplated as being part of the invention, limited only by the scope of the claims.


The invention relates to a simple, economical, and lightweight device for holding, carrying, and unreeling spools of wire when stringing barbed wire fences. The device includes a pair of leg members bent at a lower end thereof to form feet members for supporting the device on a surface, a swivel arm for holding the spool of wire for rotation thereon during unreeling, and an arm member for carrying or transporting the spool of wire. The spool of wire on the device can be held away from the body of the user while avoiding the dangers encountered with the installation and use of barbed wire.

Not Applicable.
Not Applicable.
Nine patents for improvements to wire fencing were granted by the U.S. Patent Office to American inventors, beginning with Michael Kelly in November 1868 and ending with Joseph Glidden Nov. 24, 1874, U.S. Pat. No. 157,124 for barbed wire. Barbed wire not only simplified the work of the rancher and farmer, but it significantly affected political social, and economic practices.
Since the invention of barbed wire, there has been a need for an apparatus to handle the unrolling of the wire; as can be seen by the following references to U.S. patents. Wire unreeling devices of the general type described below are well known in the art. When laying a string of wire from a spool, such as barbed wire for a fence line, the ground surface, which must be traversed, is often rough and uneven and the barbed wire itself is often difficult to handle because of its inherently hazardous nature and tendency to uncoil or backlash. Prior art devices, which are intended to overcome the foregoing difficulties, tend to become mechanically complex and somewhat unwieldy and difficult to manipulate.
There are numerous dispensers designed to aid in uncoiling and unrolling spooled and rolled materials. Typical of these is U.S. Pat. No. 6,079,663 (242/588.2) issued to Slater on Jun. 24, 2000, U.S. Pat. No. Des. 424,774 (D34/26) issued to Zarley on May 9, 2000 as well as U.S. Pat. No. 5,333,808 (242/598.3) issued to Klumpjan on Aug. 2, 1994.
Other typical patents are:
U.S. Pat. No. Des. 328,378 (D34/24) issued to Hargrove on Jul. 28, 1992.
U.S. Pat. No. 3,967,793 (242/96) issued to Walker on Jul. 6, 1976.
U.S. Pat. No. 3,820,733 (242/94) issued to Roederer on Jun. 28, 1974.
U.S. Pat. No. 3,680,807 (242/94) issued to Fortson on Aug. 01, 1972.
U.S. Pat. No. 3,341,149 (242/94) issued to Graham on Sep. 12, 1967.
U.S. Pat. No. 3,100,607 (242/86.64) issued to Wiggins on Aug. 13, 1963.
U.S. Pat. No. 3,009,667 (242/94) issued to Browne on Nov. 21, 1961.
U.S. Pat. No. 2,140,676 (242/94) issued to Hohner on Dec. 20, 1938.
U.S. Pat. No. 2,089,335 (140/92.2) issued to Brown on Aug. 10, 1937.
U.S. Pat. No. 2,067,765 (242/96) issued to Juranic on Jan. 12, 1937.
U.S. Pat. No. 2,029,953 (242/90) issued to Sutilef on Feb. 04, 1936.
U.S. Pat. No. 1,648,568 (242/391.1) issued to Stoffel on Nov. 08, 1927.
U.S. Pat. No. 1,341,484 (242/588.2) issued to Starratt on May 25, 1920.
U.S. Pat. No. 1,249,691 (242/588.2) issued to Tillman on Dec. 11, 1917.
U.S. Pat. No. 594,977 (242/391) issued to Williams on Dec. 07, 1897.
U.S. Pat. No. 589,490 (242/391) issued to Young on Sep. 07, 1897.
U.S. Pat. No. 467,499 (242/396.8) issued to Dulin on Jan. 26, 1892.
U.S. Pat. No. 6,079,663 Inventor: John E. Slater Issued: Jun. 24, 2000: a spooled barbwire dispenser discloses a swivel hook means for grasping a spool of wire being 360 degrees rotatable centrally mounted onto the underside of a rectangular shaped metal plate whereby the plate further has a handle for being grasped by the user with the handle being welded onto the top of the plate. This invention allows the swivel hook to be hooked onto the handle of a reel of wire such as barbed wire, and further allows the reel of wire to be unrolled so that the wire spool is maintained effectively in the horizontal plane as the spool is transported from one work location to the next.
U.S. Pat. No. Des. 424,774 issued to Zarley on May 9, 2000 is an ornamental design for a portable wire dispensing reel for barbed wire with wheels and a tongue for mechanical pulling.
U.S. Pat. No. 5,333,808 issued to Klumpjan on Aug. 2, 1994 is a wire unreeling device supporting a spool of wire in one position to utilize the rims of the spool as wheels and in an inverted position to hold the spool above the ground in a freewheeling manner.
U.S. Pat. No. Des. 328,378 issued to Hargrove on Jul. 28, 1992 is an ornamental design for a hand pull barbed wire dispenser mounted on wheels with an attached tongue for manual pulling.
U.S. Pat. No. 3,967,793 Inventor: David O. Walker Issued: Jul. 6, 1976 is a wire spool holder, specifically adapted for barbed wire and the like, includes freely rotatable spool engaging members and a freely rotatable holding or grasping member connected to the engaging members.
U.S. Pat. No. 3,820,733 issued to Roederer on Jun. 28, 1974 relates to maneuvering and handling devices and carriers for dual headed reels such as are employed for storing and dispensing barbed wire and has to do with a novelly constructed sectional or knockdown reel and an elongated supporting or handling frame which functions to mount the reel for roll-along use or, alternatively, for supported use on a farming machine.
U.S. Pat No. 3,680,807 issued to Fortson on Aug. 01, 1972xe2x80x94a roller assembly for rolling over the ground either by hand or by being pulled by a powered vehicle and includes opposite end large diameter wheel portions and a diametrically reduced center portion rotatable with the wheel portions and upon which a spool of wire is disposed for rotation with and unwinding from the reduced center portion of the roller assembly.
U.S. Pat. No. 3,341,149 issued to Graham on Sep. 12, 1967 is characterized by an elongated sled-like frame, which can be converted from a sled to a roll-along vehicle by attaching wheels to brackets provided for on the sled. The frame can be dragged along behind a tractor on the wheels or removing the wheels and using the frame as a push-pull type sled.
U.S. Pat. No. 3,100,607 issued to Wiggins on Aug. 13, 1963 discloses a barbed wire reel holder including a pair of wheels each having an opening there through, a continuous axle extending through the opening in each of the wheels for placing varying widths of rolls of wire.
U.S. Pat. No. 3,009,667 issued to Browne on Nov. 21, 1961 discloses a device for aiding in the unreeling of wire on a spool comprising a generally u-shaped frame having an elongated handle extending from the u-shaped frame, a transverse hollow member at the free end of the handle forming hand grips and a pair of removable circular wheels fixedly attached to the axle.
U.S. Pat. No. 2,140,676 issued to Hohner on Dec. 20, 1938 is a wire-handling device comprising a substantially u-shaped frame, including a handle and parallel legs on the handle, a transverse axle having one end connected to the free end of one of the legs adapted for insertion through a spool of wire.
U.S. Pat. No. 2,089,335 Inventor: G. L. Brown Issued: Aug. 10, 1937xe2x80x94this United States Patent discloses a method for spooling barbed wire wherein all of the barbs project inwardly and for carrying purposes there is provided a stirrup or carrying frame the cross piece between the two arms serving as a handle.
U.S. Pat. No. 2,067,765 Inventor: Walter Juranic Issued; Jan. 12, 1937xe2x80x94this United States Patent discloses a reel holding device which has the reel of material rotatable suspended so as to facilitate the discharge or unreeling of the material and when the device is not in use it may be collapsed to a compact form to occupy a minimum of space in storage.
U.S. Pat. No. 2,029,953 issued to Sutilef on Feb. 04, 1936 discloses a wire carrying reel comprising a hauling frame comprising a rod or tube which is bent into a u-shape producing a pair of shafts for pulling or pushing the implement using the wheels mounted in the rear end of the frame.
U.S. Pat. No. 1,648,568 issued to Stoffel on Nov. 08, 1927 relates to a winch structure upon which a spool containing barbed wire may be mounted and the rotation of the spool by rolling the structure along the ground will cause the barbed wire to be fed off the spool.
U.S. Pat. No. 1,341,484 Inventor: Harold E. Starratt Issued: May 25, 1920xe2x80x94this United States Patent discloses a single piece of resilient metal bent to form a grip member, a handle member having two straight portions adapted to lie parallel to each other, a pair of oppositely extending arms at the end of said handle portion, jaw members adjustably mounted on the ends of said arms, bearing members carried by said jaws members, means for securing the jaw members in their adjusted positions on the arms, and a keeper adapted to engage the portions of the handle member to draw the bearing members into a predetermined relation to each other.
U.S. Pat. No. 1,249,691 issued to Tillman on Dec. 11, 1917 is a reel for supporting barbed wire during the application of the wire to a fence; providing a reel, which may be readily carried by two workmen.
U.S. Pat. No. 594,977 issued to Williams on Dec. 07, 1897 is a wire unwinding device consisting of a u-shaped bail having one end terminated in the form of an eye, a side bar having one end adapted to loosely engage the eye, and the other end arranged to engage the opposite end of said bail.
U.S. Pat. No. 589,490 issued to Young on Sep. 07, 1897 discloses a device for distributing fence wire, two side bars having handles at one end and aligned bearings at opposite end allowing for the distributing of up to three rolls of wire at the same time.
U.S. Pat. No. 467,499 issued to Dulin on Jan. 26, 1892 discloses a fence wire reel and tightener consisting of a reel adapted to fit loosely on an axle with transporting wheels.
While these wire spool dispensers, described by the previously issued patents, may be suitable for the purposes for which they were designed, they would not be as suitable for the purposes of the present invention, as hereinafter described.
A primary object of the present invention is to provide a light weight apparatus, which can be used by one person to hold and carry a spool of wire, specifically barbed wire, and to dispense said wire while moving from one location to another over all types of terrain such as gullies, rocky ground, smooth ground, between and around trees, through vines, leaves, and other debris; while keeping the roll of wire, specifically barbed wire, from coming into contact with the person or any of the above mentioned encumbrances.
Another object of the present invention is to provide a wire holder, carrier, and dispenser or unreeler, specifically a barbed wire holder, carrier, and dispenser or unreeler, having a handgrip or handle, which will allow for easy handling of spools of wire, specifically barbed wire, by one person.
Yet another object of the present invention is to provide a method for holding a spool or reel of wire, and means for engaging a spool or reel of wire, a method for unreeling the spool or reel of wire without the wire, specifically barbed wire, touching the ground which will prevent trash, leaves, vines, and other debris from becoming entangled in the roll of wire.
Still yet another object of the present invention is to provide a means for the device to stand upright when not in use as well as to provide the means for the device to move easily over the ground surface thus eliminating the need for wheels to be attached to the device thereby preventing debris from becoming entangled in same.
Generally, spools of wire are heavy and cumbersome to handle. With respect to barbed wire, the dangers encountered with the installation and uses thereof are well known and self-evident. In manual installations, spools of barbed wire are unwound and erected by, usually, two or more persons. Because of the hazards encountered with the barbs, one person controls and guides the unreeling of the spool while the other person installs the wire. Such two person installations are expensive and time consuming.
The present invention provides a device, particularly adapted for barbed wire, which enables the holding, carrying, unreeling, and installation of barbed wire by one person, while avoiding the problems and dangers encountered with the installation and use of barbed wire.
In accordance with the present invention there is provided a wire spool holder, carrier, and unreeler device particularly adapted for use with spools of barbed wire. The device hereof generally comprises a means for engaging a spool of wire, a means for grasping or holding the spool of wire, a means for carrying or transporting the spool of wire, and a means for unreeling the spool of wire.
The means for engaging the spool allows the spool of wire to rotate freely, permitting the unreeling of the wire from the spool. The means for engaging is connected to the means for grasping such that a spool of wire engaged therewith can be held away from the body of the user, thus avoiding the dangers encountered with the installation and use of barbed wire.
In the description reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments will be described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural changes may be made without departing from the scope of the invention.
For a more complete understanding of the present invention, reference is made to the following detailed description and accompanying drawings.

Barbed wire holder, carrier, and unreeler


Basic cleaning compositions using toxicologically-acceptable ingredients for cleaning fruits and vegetables are provided. Liquid formulations comprising detergent surfactant, such as oleate, alcohol ethoxylates, etc., and neutralized phosphoric acid are sprayed onto apples, lettuce and the like to remove soil and unwanted deposits, especially wax. Articles for applying the compositions to produce by spraying are disclosed. Use of the compositions for disinfectancy/sanitization of produce and cleaning/disinfectancy/sanitization of non-food inantimate surfaces are disclosed.

The present invention relates to methods for removing dirt and other unwanted residues from produce, e.g., fruits and vegetables, which is intended for ingestion by humans or lower animals and to detersive compositions, especially in liquid form, which are especially suitable for practicing said methods.
It is well-known and appreciated by consumers that fruits and vegetables should be thoroughly washed prior to ingestion in order to remove soils and other unwanted residues which may be undesirably clinging to the surfaces thereof In addition, some consumers wish to remove the artificial xe2x80x9cwaxyxe2x80x9d coatings which may be applied to some fruits to retard moisture loss for increased storage life and to enhance their appearance. It has been estimated that 95% of consumers recognize the need for thorough washing but, ordinarily, only use tap water for this purpose. On the order of 5% of those consumers who do wash their vegetables use a household cleaner, typically a liquid dishwashing product, to help ensure cleanliness. However, dishwashing products are not specifically intended for such use, inasmuch as they are usually designed to provide high, persistent suds which makes them inconvenient to remove from the fruits or vegetables which have been washed therewith. It will also be appreciated that the formulation of truly effective compositions, especially those which can be used safely by individual consumers, for washing fruits and vegetables presents a unique problem to the formulator, inasmuch as many art-disclosed cleaning ingredients would, presumably, not be desirable for use in direct contact with foods where they might not be fully removed.
Moreover, it would be especially desirable to provide effective, toxicologically-acceptable cleaning compositions for fruits and vegetables in the form of substantially low-sudsing liquid solutions which are clear or which have only minimal haziness. Liquid solutions are convenient for the user, since they can be applied directly to soiled fruits and vegetables, followed by rinsing in tap water. The clarity of the liquids connotes cleanliness to the user and is thus highly desirable. Low sudsing is an important attribute so that removal of the solution by rinsing is achieved quickly and easily. It would also be of advantage if such compositions could be provided in the form of concentrates, which could be diluted by the consumer before use and/or applied to the fruits and vegetables as a direct spray-on.
Unfortunately, many toxicologically-acceptable cleaning ingredients do not meet the aforesaid requirements for clear, low-sudsing, dilutable liquid products. Many detersive surfactants form cloudy or even opaque suspensions, even in soft water. Of course, many surfactants are specifically designed to be high sudsing. Still others form relatively intractable phases in their concentrated form.
It has been disclosed that soap and/or certain nonionic surfactants, properly formulated, e.g., with water-soluble oleate or laurate salts and other ingredients can provide liquid compositions having the desired properties described above. It has also been disclosed that preferred compositions can be formulated in the basic pH range. Even when such basic compositions do have a soapy feel, they are preferred over the acidic compositions herein for removing artificial waxy coatings, especially from fruit such as apples. However, the invention also comprises basic compositions having less soapy feel. It has now been discovered that the addition of neutralized phosphoric acid provides even better cleaning, especially of waxy material, even at the same pH.
The use and selection of cleaning ingredients for the purpose of washing fruits and vegetables is described by the United States Code of Federal Regulations, Title 21, Section 173.315: xe2x80x9cIngredients for use in washing or lye peeling of fruits and vegetablesxe2x80x9d. These regulations restrict the ingredients that may be used for direct contact with food to those described as xe2x80x9cgenerally regarded as safexe2x80x9d (GRAS), and a few other selected ingredients. These sections also provide certain limitations on the amount of material that can be used in a given context.
Among these ingredients, the experienced formulator will find only a few ingredients which can provide effective cleaning of hydrophobic residues, such as waxes, oils, or man-made chemical residues such as pesticides. It is recognized these types of residues are removed most readily by surface active ingredients in water, or by organic solvents largely in the absence of water. Other types of soils, especially particulate insoluble soils that do not readily disperse in water, are effectively removed by surface active materials in water, especially when aided by complex anionic salts, such as citrates (polycarboxylates), or polyphosphate salts.
Within this limited group of ingredients the range of effective cleaning compositions well suited to the task of cleaning fruits and vegetables, especially as practiced by individual consumers, have not been previously described. It is desirable to formulate liquid compositions which are amenable to either direct application to produce, preferably by spray application, or could be provided in suitable concentrated form to allow convenient dilution in a bowl or sink of water for washing of produce by immersion. Further, it is desirable if the compositions are low sudsing, and easily rinsed, without leaving residue. Preferred compositions should be mild to the hands, especially for direct application.
Food Chemical News, Inc., 1991, p. 334.1, reports that PEG 200-9500 has been cleared under xc2xa7178.3750 as a component in articles for use in contact with food (Fed. Register, Oct. 15, 1968). Nonetheless, for washing -produce, polyethylene glycol should be affirmed as GRAS.
The present invention encompasses methods for cleaning produce, especially fruits and vegetables, (and compositions, as disclosed hereinafter, for practicing said methods) at a basic pH. The present invention comprises several aspects including:
I. A method for cleaning produce comprising contacting the surfaces of said produce by direct application of an aqueous cleaning solution typically comprising:
(a) from about 0.01% to about 15% of C8-C18 fatty acid;
(b) optionally, from about 0.1% to about 4% by weight of nonionic surfactant, especially ethoxylated and/or propoxylated adducts of aliphatic C12-18 alcohols, but preferably less than about one eighth of the amount of said fatty acid;
(c) optionally, from about 0.1% to about 4% by weight of organic polycarboxylic acid, preferably citric acid;
(d) optionally, up to about 0.2% by weight of base-stable anionic surfactant such as the alkali or alkaline earth salts of dodecylbenzene sulfonate;
(e) optionally, toxicologically-acceptable basic buffer such as potassium and/or sodium basic materials, e.g., the hydroxides and/or salts of carbonate and/or bicarbonate;
(f) optionally, toxicologically-acceptable preservative;
(g) optionally, but preferably, from about 0.05% to about 10%, preferably from about 0.1% to about 5%, more preferably from about 0.3% to about 2% of phosphoric acid;
(h) optionally, at least about 0.05%, preferably from about 0.1% to about 10%, most preferably from about 0.25% to about 3.0%, by weight, of water-soluble polyethylene glycol having a molecular weight of about 200, or higher; and
(i) the balance comprising an aqueous carrier selected from water and, optionally, low molecular weight, toxicologically-acceptable organic solvent such as ethanol, glycerol, etc.;
all of the acidic materials above being, of course, neutralized under the alkaline conditions of the product, preferably neutralized with sodium and/or potassium, preferably potassium, compatible basic material, wherein said.aqueous solution has a pH in the range of 9.5 or greater, preferably more than about 11, and even more preferably from about 11.5 to about 12.5, and said composition preferably being essentially free of any material that is not toxicologically acceptable.
The inventions disclosed herein preferably encompass compositions for use in a method for cleaning fruits and vegetables at a basic pH above about 9.5, comprising:
(a) from about 0.01% to about 15% of C8-C18 fatty acid which is neutralized, preferably a member selected from the group consisting of sodium or potassium oleate (preferred), or from about 0.5% to 10% by weight of sodium or potassium laurate;
(b) optionally, from about 0.1% to about 4% by weight of nonionic surfactant, especially ethoxylated/propoxylated adducts of aliphatic C12-18 alcohols, but preferably less than about one eighth of the amount of said fatty acid;
(c) optionally, but preferably, from about 0.2% to about 4% by weight of potassium and/or sodium polycarboxylate, having detergent building capability and preferably being derived from natural sources, such as potassium and/or sodium citrate, as a dispersant for particulate soils;
(d) optionally, up to about 0.2% by weight of base-stable anionic surfactant such as the alkali or alkaline earth salts of dodecylbenzene sulfonate;
(e) optionally, toxicologically-acceptable basic buffer such as potassium and/or sodium basic materials, e.g., the hydroxides and/or salts of carbonate and/or bicarbonate;
(f) optionally, toxicologically-acceptable preservative;
(g) optionally, but preferably, from about 0.05% to about 10%, preferably from about 0.1% to about 5%, more preferably from about 0.3% to about 2% of phosphoric acid; and
(h) optionally, at least about 0.05%, preferably from about 0.1% to about 10%, most preferably from about 0.25% to about 3.0%, by weight, of water-soluble polyethylene glycol having a molecular weight of about 200, or higher;
(i) the balance preferably comprising aqueous carrier selected from water and, optionally, low molecular weight, toxicologically-acceptable organic solvent such as ethanol, glycerol, etc., preferably selected from water and water-ethanol;
wherein said aqueous cleaning solution has a pH of 9.5 or greater, and preferably employs carbonate salt, or salts, as buffer (e), preferably with hydroxide base, to provide a pH of from about 11 to about 12.5, more preferably from about 11.5 to about 12.5. The compostions can also be formulated as concentrates, in which at least part of (i) is removed and the levels of the remaining ingredients are adjusted to complete the formula. In all of the above lists of components, if an ingredient can be classified in more than one place, it will be classified in the first place it can appear.
A more specific method for cleaning fruits and vegetables at a basic pH, preferably more than about 9.5, comprises contacting the surfaces of said fruits and vegetables with an aqueouscleaning solution comprising potassium oleate, preferably at a level of more than about 0.5%. Potassium oleate is mild, rinses well, has minimal odor, is effective in removing unwanted materials, especially wax, from apples, does not oversuds, and is very safe, even when the composition is misused and the vegetable, or fruit, etc., is not completely rinsed. Therefore, it is a uniquely preferred surfactant for use in cleaning food materials like vegetables and fruits. The potassium cation is more useful than the sodium cation, especially in the absence of polyethylene glycol, since the potassium oleate is quite soluble whereas the sodium oleate tends to form a less soluble soap, especially at low temperatures.
A concentrated, alkaline method for cleaning produce comprises contacting the surfaces of produce with a cleaning solution containing from about 0.5% to about 15%, preferably from about 0.75% to about 8%, more preferably from about 1% to about 5%, detergent surfactant, preferably one that is GRAS, and more preferably said oleate surfactant, said cleaning solution having a pH of from about 9.5 to about 12.5, preferably from about 11 to about 12.5, especially when the detergent surfactant is a soap such as the said oleate, more preferably from about 11.5 to about 12.3. Such compositions when used in an effective amount to clean apples coated with wax, will provide more effective removal of the wax when combined with the neutralized phosphoric acid. Removal of wax from apples is one of the most difficult cleaning tasks and therefore is indicative of overall superior performance. It is important to remove as much wax as possible to minimize the amount of any undesirable materials that may be trapped by the wax.
Another preferred variation in the above methods for cleaning produce involves placing said cleaning solutions in a spray container to provide a spray of said solution to distribute the said solution, or solutions, over the surfaces of the produce while utilizing only a minimum amount of the cleaning solution and minimizing the exposure of the remaining solution to the atmosphere, where the solution is more likely to be contaminated and/or exposed to oxygen, both of which tend to cause undesirable changes in the solutions from aesthetic and/or performance considerations. In such spray processes, there is only need for a relatively small amount of material in the package, and for individual consumer use, this is desirable, since some consumers will not be able to manipulate large weights. For individual consumer usage, typically, the container will contain no more than about two gallons (about eight liters), preferably no more than about one gallon (about four liters), especially when the container is a spray container, even one that has a tube that permits the spray device to be manipulated while the bulk container remains in place. More preferably such spray containers contain about one liter, or less, of cleaning solution.
The invention encompasses basic cleaning compositions in both concentrated and dilute forms, especially adapted for practicing said methods. (In the following disclosure, the lower amounts of the specified ingredients denote the dilute forms of the compositions herein and the higher amounts denote the concentrated forms which are typically diluted by a factor of from about 2 to about 3.) The compositions can be concentrated even more to non-aqueous liquids or solids according to the teaching in U.S. Pat. No. 5,280,042, Lopes, said patent being incorporated by reference. Such compositions include the following.
A composition for cleaning fruits and vegetables at a basic pH, comprising:
(a) from about 0.1% to about 15%, preferably from about 1% to about 5%, by weight of a member selected from the group consisting of sodium or potassium oleate (preferred), sodium or potassium laurate, or mixtures thereof;
(b) optionally, from about 0.1% to about 4%, preferably about 0.3% to about 1.0%, by weight of nonionic surfactant as described above;
(c) from about 0.2% to about 4% by weight of polycarboxylic acid salt, especially potassium hydrogen citrate;
(d) from about 0.3% to about 5% of ortho-phosphoric acid; and
(e) the balance comprising aqueous carrier selected from water and water-ethanol;
wherein said composition has a pH of 9.5 or greater.
Preferably, the basic compositions herein contain from about 0.5% to about 1.5% by weight of potassium, and/or sodium, carbonate and/or bicarbonate buffer and have a pH of from about 11.5 to about 12.5.
Preferred compositions for use herein in a concentrated alkaline method contain from about 0.1% to about 15%, preferably from about 0.5% to about 8%, more preferably from about 1% to about 5%, detergent surfactant, preferably one that is GRAS; from about 0.3% to about 5% of ortho-phosphoric acid and have a pH of from about 9.5 to about 12.5, preferably from about 11.5 to about 12.3. Such compositions, when used in an effective amount to clean apples coated with wax, will provide more effective removal of the wax. Removal of wax from apples is one of the most difficult cleaning tasks and therefore is indicative of overall superior performance.
The present invention also encompasses detersive compositions with an improved tactile impression which are especially adapted for cleaning fruits and vegetables, comprising:
(a) at least about 0.1%, preferably from about 0.5% to about 8%, most preferably from about 1% to about 5%, by weight, of a C12-C18 fatty acid or salt thereof,
(b) at least about 0.05%, preferably from about 0.1% to about 10%, most preferably from about 0.25% to about 3.0%, by weight, of water-soluble polyethylene glycol having a molecular weight of about 200, or higher;
(c) from about 0.1% to about 5% of neutralized ortho-phosphoric acid; and
(d) water or water-ethanol fluid carrier, said composition having a basic pH.
The balance of the composition can comprise various optional adjunct materials, pH-adjusting agents, perfumes or essences, preservatives and the like.
In a preferred mode, component (b) has a molecular weight in the range from about 300 to about 9500.
Typical compositions herein are wherein component (a) is potassium oleate, and wherein the weight ratio of (a):(b) is in the range from about 1:2 to about 30:1, preferably from about 1:1 to about 15:1.
The compositions having improved tactile impression are typically formulated in the basic pH range, preferably from about pH 9.5 to about pH 12.5. Preferred compositions have a viscosity at room temperature of less than about 100 centipoise, preferably less than about 50 centipoise for sprayable compositions.
Preferred compositions for use herein contain only materials that are GRAS, including, of course, direct food additives affirmed as GRAS, to protect against possible misuse by the consumer. Traditionally, most suggestions for cleaning of fruits and/or vegetables have contemplated a commercial scale where there is typically more control over the conditions, especially the amount and thoroughness of rinsing. The present invention, especially the methods involving use of hand held trigger activated spray means are primarily/solely suitable for use by individual consumers so that it is essential that extra safety be built into the product. Failure to rinse thoroughly after cleaning is less of a concern if all of the ingredients are GRAS. This is especially important when concentrated basic compositions suitable for removal of wax from apples are used. The larger amounts of materials needed for removal of wax create an heretofore unknown level of risk for the individual consumers, many of whom are not likely to read, or follow, instructions which would permit safe use of non-GRAS materials.
The ingredients in the above compositions are preferably selected and used in proportions which provide substantially clear compositions. xe2x80x9cSubstantially clearxe2x80x9d includes only minimal haziness, and preferably the compositions are completely clear. The ingredients are also selected to have minimal odor, both initially and after storage. The lack of odor is especially important in compositions for use on food. The compositions preferably have a viscosity that is more than about 2 centipoise, preferably more than about 10 centipoise when at rest, but thin under shear to permit easy dispensing, especially from spray containers.
Below pH about 9.7, the compositions can exhibit some objectionable fatty acid odor. Even at the optimal pH""s above 11, some odor can persist. In order to mask this odor, the compositions can contain a GRAS perfume, or essence, ingredient. Especially preferred for this use are oils derived from citrus fruit, e.g., oranges, lemons, limes, grapefruits, tangerines, tangelos, etc. which contain relatively large amounts of terpenes.
All documents cited herein are incorporated herein by reference.
The following toxicologically-acceptable ingredients are used in the preparation of the preferred compositions herein. By xe2x80x9ctoxicologically-acceptablexe2x80x9d is meant that any residues from the ingredients of the compositions which may remain on the fruits or vegetables cleansed therewith are safe for ingestion by humans and/or lower animals.
The nonionic surfactant is preferably selected from materials known in the art, such as alkylene oxide (ethylene oxide and/or propylene oxide) adducts of C10-18 aliphatic alcohols or acids, C10-18 aliphatic alcohol adducts of glucose (alkyl polyglucosides). The specific nonionic surfactant selected ideally has a hydrophilic-lipophilic balance (HLB) greater than about 10, and a cloud point above about 35xc2x0 C. in the composition. The United States Code of Federal Regulations (CFR) specifically describes an ethylene oxide/propylene oxide adduct of C12-18 aliphatic alcohol of molecular weight of about 800. Such a material is available as PLURAFAC RA-20 (BASF).
In the basic compositions containing soap, the alkoxylated alcohol functionsmainly as a dispersant for any soap curd which may form during the cleansing operation. Further, it is recognized that the selection of non-nitrogen containing nonionics can minimize the possibility of microbial growth in the dilute surfactant compositions.
The acidic compositions herein are preferably formulated using an unsaturated fatty acid; oleic acid is preferred and convenient for this use. However, the particular oleic acid that is selected should preferably be low in polyunsaturates, e.g., contain less than about 10%, preferably less than about 7%, more preferably less than about 5%, polyunsaturated acid minor components, and will typically have an Iodine Value (IV) of from about 70 to about 100, preferably from about 83 to about 95, more preferably from about 85 to about 90. Polyunsaturated fatty acids are not preferred herein, due to odor problems. However, this is primarily from aesthetic considerations since such acids are effective in cleaning. The amount of polyunsaturated fatty acids should be less than about 8%, preferably 0%. The amount of polyunsaturated fatty acids with more than about two double bonds should be less than about 1%, preferably 0%. Saturated fatty acids are unacceptable as they have limited solubility for longer chainlength materials (xe2x89xa7C12), or have unacceptable odor (xe2x89xa6C10). For example, stearic and/or tallow fatty acids soaps, even potassium soaps, do not have enough solubility at room temperature, where most produce cleaning is done by individual consumers, to formulate even compositions containing the minimum of about 0.1% soap required for acceptable cleaning. Other specific solubilizing surfactants in higher proportions would be required to solubilize these saturated fatty acids. Pamolyn 100 FGK oleic acid is a good example of a suitable commercial fatty acid.
Phosphoric acid is an extremely desirable component for improving the removal of, e.g., wax from apples. The advantage is not due solely to pH since the improvement is observed at any pH. E.g., as disclosed hereinafter, when the pH is varied from about 11 to about 12, the results are superior when the neutralized ortho-phosphoric acid is present. The result is also not due to any ability of the neutralized phosphoric acid to act as a builder to inhibit the problems associated with water hardness, since the results are improved when the compositions are used full strength by application directly on the waxed surface.
It is surprising that the neutralized orthophosphoric acid provides such a large benefit. The advantage is especially noticed when the compositions are used full strength, e.g., by spraying the composition directly onto the surface of the produce.
The water-soluble polyethylene glycol polymer (PEG) employed herein is the known article of commerce and is available under a variety of trade names, of which CARBOWAX (Union Carbide Corporation) is exemplary. PEG""s in the average molecular weight range of from about 200 to about 20,000 can be used herein, and PEG as CARBOWAX in the average molecular weight range of at least about 200, typically 300 to about 9500, is convenient and preferred. As disclosed above, the compositions herein will comprise at least about 0.05%, by weight, of the PEG and will typically comprise from about 0.1% to about 10%, by weight, of PEG. The amounts used can vary with the molecular weight of the PEG, the amount of oleate or other fatty acid used in the composition, the desired viscosity of the composition, and like factors within the discretion of the formulator. The following Table 1 illustrates the variation in viscosity which can be effected using various levels of PEG and varying PEG molecular weights in a liquid composition (Control) comprising 3% potassium oleate. Table 1 also illustrates the effect of sodium benzoate (Bz) on viscosity.
In a typical mode, the preferred compositions herein that have an improved tactile impression will comprise oleate:PEG weight ratios in the range from about 1:2 to about 30:1, preferably from about 1:1 to about 15:1.
The compositions herein which contain the polyethylene glycol are characterized not only by their excellent cleaning performance and sudsing/rinsability properties, but also by their improved viscosity properties and improved xe2x80x9cfeelxe2x80x9d. While, as disclosed above, the improved viscosities of the compositions herein are readily demonstrated quantitatively using standard measurement techniques, the improved feel of the compositions which come into contact with the users"" hands is a qualitative tactile impression. However, this improved, xe2x80x9cnon-slipperyxe2x80x9d, xe2x80x9cnon-soapyxe2x80x9d improvement in skin feel can be demonstrated by rubbing Test (PEG-containing) and Control (no PEG) compositions on the hands or inner forearms of volunteer graders. Even in such rudimentary tests, the graders can readily distinguish the improved tactile impression of the compositions made in accordance with this invention.
Optionally, base stable anionic surfactants can be employed, as allowed by the United States Code of Federal Regulations, Title 21, Section 173.315. Preferred are salts of dodecylbenzene sulfonate, typically at levels up to 0.2%. Also described in the CFR are phosphate esters of ethylene and/or ethylene/propylene oxide adducts of aliphatic alcohols, dioctyl sulfosuccinate, and 2-ethylhexyl sulfate.
The organic polycarboxylic acid, or salt thereof, e.g., citric acid, or sodium and/or potassium citrate, and/or ethylenediaminetetraacetic acid, or sodium and/or potassium ethylenediaminetetraacetate, are standard items of commerce and are GRAS. Other organic poly carboxylic acids, especially those that are GRAS, such as tartaric, malic, etc. acids, can also be used. When formulating the basic formulations herein, it is preferred to use the potassium salt, as compared with the sodium salt, to provide ease of formulatability. Complex phosphates can also be used, but are generally avoided due to regulatory considerations.
Toxicologically-acceptable basic buffers can be used in the compositions herein to maintain product pH in the base range. For ease of formulatability, it is highly preferred that such basic buffers be in their potassium salt form. Potassium citrate is a preferred dispersant for particulate soils. Potassium carbonate is a convenient and preferred basic pH buffer. Sodium bicarbonate is a highly desirable material to add to the compositions of this invention as a part of the buffering system since it is readily available as baking soda in food grade and is therefore relatively inexpensive, while providing a highly desirable purity to the composition. Compositions formulated with a mixture of potassium and sodium cations in molar ratios of from about 1:1 to about 10:1, preferably from about 2:1 to about 8:1, more preferably from about 4:1 to about 5:1 potassium to sodium, e.g., as provided by mixtures of potassium hydroxide (hydrate) and sodium bicarbonate, have desirable Theological properties. The compositions are sufficiently viscous, so as to cling to the fruit or vegetable until spread, but are readily dispensed, e.g, by means of a spray device, either aerosol or finger-activated pump. The levels and identities of the ingredients are adjusted to provide products having the desired viscosities as set forth herein, e.g., more than about 2, preferably more than about 5, more preferably more than about 10 centipoise when at rest, and less than about 150, preferably less than about 100, more preferably less than about 50 centipoise under shear of xe2x89xa7xcx9c1000 secxe2x88x921.
The ability of the preferred compositions containing mixtures of both sodium and potassium cations to shear thin is important to promote easy dispensing, especially when the compositions are sprayed, while maintaining the ability to be thick, cling, and delay run off after being applied to the produce.
The pH is preferably not greater than about 12.5, and especially does not contain large amounts of buffer at higher pHs for consumer safety, especially when the compositions are sprayed.
Formulating the present compositions at high pH reduces the tendency for biological growth of contaminants, such as bacteria, fungi, or molds. At neutral pH, an increased reliance on preservatives is required to insure the lack of biological growth through contamination in making or in use. Standard food-grade preservatives such as ethylenediaminetetraacetic acid and/or the salts thereof, at a level of from about 0.01% to about 0.2% of ethylenediaminetetraacetic acid, or its sodium and/or potassium salts, can be used although, in general, the basic pH compositions herein do not require a preservative.
The use of commercial oleic acid, or oleate salts, can be complicated by development of off-odors and/or yellowing of the compositions in which they appear. These undesirable properties are believed to be caused by complex side reactions initiated by the reaction of oxygen with primarily the polyunsaturated components of the fatty acid stock. These results can be avoided, or minimized, by avoiding contact with air, or by controlling the quality of the fatty acid stock so that the amount and type of polyunsaturates are minimized as described above, and/or by the addition of antioxidants.
It has been found, that the addition of tocopherols (e.g., Vitamin E, or tocopherol acetates) in alkaline formulations is advantageous, as they do not degrade, nor do they impart a strong color. They inhibit the development of off-odors for extended periods of time so that the need for masking scents is minimized, or eliminated, particularly for oleic acid stocks of high quality, as described above. The use of butylated phenols, such as BHT and BHA is also useful, but the quantity should be limited to avoid imparting colors to the compositions. Other food grade antioxidants such as Vitamin C and sulfites, are desirable to prevent deterioration of the compositions by the action of oxygen, but care must be taken since vitamin C can suffer color degradation and sulfites can cause odor problems. Sulfites also have been the target of potential health concerns.
The major proportion, e.g., more than about two thirds, (typically, 80%-98%, by weight) of the compositions herein comprises water as the solubilizing carrier for the ingredients. As noted in the Examples hereinafter, water-ethanol can also be employed and is especially preferred when formulating the basic pH compositions herein. The ethanol level preferably should not exceed 2% in the solution used to clean the produce, to avoid an alcoholic odor, especially when spraying. Other compatible, water-soluble, low molecular weight solvents such as glycerol can also be used.
The compositions herein are preferably used by placing them in a package comprising either an aerosol container or a non-aerosol spray device xe2x80x9cspray means.xe2x80x9d Said spray means is any of the manually activated, preferably xe2x80x9ctrigger-type,xe2x80x9d means for producing a spray of liquid droplets as is known in the art. Typical spray means are disclosed in U.S. Pat. No.: 4,082,223, Nozawa, issued Apr. 4, 1978; U.S. Pat. No. 4,161,288, McKinney, issued Jul. 17, 1979; U.S. Pat. No. 4558,821, Tada et al., issued Dec. 17, 1985; U.S. Pat. No. 4,434,917, Saito et al., issued Mar. 6, 1984; and U.S. Pat. No. 4,819,835, Tasaki, issued Apr. 11, 1989, all of said patents being incorporated herein by reference. The spray bottle, or container can be any of the ones commonly used for containing hard surface cleaner detergent compositions. Examples of bottles are those in U.S. Design Pat. Nos.: 244,991, Weekman et al., issued Jul. 12, 1977; and 275,078, Wassergord et al., issued Aug. 14, 1984, said patents being incorporated herein by reference.
The spray means herein can also include those that incorporate a compatible propellant gas into the liquid and those that will foam even detergent compositions having a viscosity of less than about 15 cps. The device can also be one that can be adjusted to either give a liquid spray or a foam. The spray means herein are typically those that act upon a discrete amount of the composition itself, typically by means of a piston that displaces the composition and expels the composition through a nozzle to create a spray of thin liquid.
Preferred articles include the compositions herein that are suitable for use in the processes described herein, in a package that can provide a spray. Such articles are not widely marketed. This is surprising in view of the clear advantages for such products for use by individual consumers. The typical use involves treating individual items of produce, which would make preparation of a xe2x80x9cbathxe2x80x9d wasteful.
In a preferred process for using the products described herein, and especially those formulated to be used at full strength, the product is sprayed onto the food product to be cleaned, rubbed, rinsed and/or wiped off with a suitable clean material like cloth, sponge, a paper towel, etc.
Surprisingly, the compositions and processes described herein can provide effective disinfectancy/sanitization. In order to provide good kill of microorganisms, especially bacteria, one should use high concentrations and/or longer exposure times. Typically, the products should be used full strength and allowed to remain on the produce for at least about one minute, preferably at least about five minutes, and, for some microorganisms, even ten minutes may be required. Longer exposure times (i.e., the time that the bacteria are in contact with the product) give better antimicrobial benefits. The importance of time depends both on the pH of the product and on the formula concentration. At high pH (xe2x89xa711.5) and high concentrations, antibacterial efficacy is achieved quickly. At lower pH values (pHxe2x89xa611) and lower formula concentrations, a longer period of exposure time is required to achieve the same efficacy.
Higher pHs are also better, in general. This factor is important for the product""s performance on the Gram negative bacteria, e.g., Escherichia coli and Pseudomonas species. Higher product pH""s produce quicker and more complete kill. The opposite is true for the Gram positive bacteria, e.g., Staphylococcus aureus. Performance is equal to, or slightly better, as the pH is lowered from 11.5 to 9.5. However, this is only true when the formula contains oleic acid.
As stated above, higher formula concentrations (when done independently of pH) enhance the antimicrobial efficacy of the product. The presence of oleic acid is the key factor for the performance on Gram positive organisms like S. aureus, while the pH is probably a bigger factor for the Gram negative bacteria, e.g., E. coli and Pseudomonas species.
Packaging the products herein in a container with instructions for usage in terms of timing and avoidance of dilution in order to provide disinfectancy/sanitization, will help the individual consumer by providing information for proper usage in order to remove/kill microorganisms. It is a special advantage of the product that it can be used for this purpose at a time in the food production process where recontamination is minimized.
The compositions can also be used for cleaning (especially spot removal), disinfectancy, or sanitization, on non-food (i.e., any surface which is not used as food, even those which are not in contact with food), inanimate, household surfaces, especially those used in food production and other food-contacting surfaces (surfaces that come in contact with food). E.g., cutting boards, counter tops, utensils, dishes, colanders, sinks, sponges, towels, dish cloths, cloth napkins (serviettes), table cloths, and other surfaces that come in contact with food. It is desirable to disinfect/sanitize before the surfaces come in contact with the food, and is desirable to redisinfect/sanitize whenever the surfaces become recontaminated. The products herein, containing all GRAS ingredients, are perfect for this purpose. On hard surfaces, of course, the compositions can be removed, after sufficient time has elapsed, by rinsing or by absorption/wiping with an appropriate object, e.g., paper towel, sponge, squeegee, etc. Rinsing is still preferred.
The compositions of this invention can also be used to treat/clean other non-food inanimate household surfaces, such as fabrics, e.g., clothing, shoes, and shower curtains, especially those that are used by infants, especially toys, diapers (napkins), and bibs. The contaminated fabrics can be disinfected/sanitized, then rinsed off or washed, while minimizing the risk if the infant puts the fabric or other article in its mouth. The fabric can be treated totally, or by spot treatment, then the composition is removed, e.g., by rinsing/washing, absorbency, and/or mechanical force.
For fabrics, the pH of the compositions is preferably below about 11.5, more preferably below about 11.
For fabric and hard surfaces, the distribution of the compositions of this invention can be achieved by using a spray device, a roller, a pad, etc., or dipping in a xe2x80x9cbathxe2x80x9d of said compositions. Spraying is a preferred method.
All parts, percentages, and ratios herein are xe2x80x9cby weightxe2x80x9d unless otherwise stated. All number values are approximate unless otherwise stated.
The following Examples illustrate the compositions and processes of this invention, but are not intended to be limiting thereof The exemplified basic liquid compositions can be prepared at pH 9.5-12.5 by dissolving the ingredients in water or water-ethanol using conventional mixing apparatus. In a convenient mode, water is placed in a mixing vessel. Potassium hydroxide, the ortho-phosphoric acid, any citric acid, any bicarbonate, glycerine (processing aid), and any ethanol are added in the named sequence, with stirring. The oleic acid is added with high shear and stirring is continued. The PEG (which can conveniently be predispersed in water) is then added. The optional perfume ingredients can be added any time after the oleic acid has been dissolved in the mixture.

Cleaning/sanitizing methods, compositions, and/or articles for produce